Model Output Discussion - Staying cold into the new year

[radiohead]

[Stu_London]

2 minutes ago, Scott Ingham said:

It was consistent from the moment it modelling the beast which was 2 weeks after the ssw but the charts leading up to modelling that were all over the place. 

Youll see if you go on the forum archive it was mayhem!

 

Absolutely

Similar in 2013 - the period leading up to the event is where the main stress occurs - after the event, they tend to settle on a pattern.

Bit like throwing a pack of cards in the air. At the moment they are in mid air - when they land, we will see if the Aces are face up!

[Griff]

2 minutes ago, Griff said:

GFSP is going up! 

Very consistent GFSP considering with previous... 162

[Snowy L]

Perfect wall of Atlantic lows preventing a west based -NAO.

[Allseasons-Si]

It's similar to the pub run last night with the northerly...

 

[sheikhy]

Funny thing is this gfs still has uppers of -6 to -8 from 72 hours all the way to 192 hours!!!!its better than the ecm!!!

[Battleground Snow]

I declare the first BOOM of my netweather career!

 

[Sky Full]

Quite a difference between them....

1:00      8th January. 

12z    

18z :  

I know which one I prefer....  

[radiohead]

So much better than the 12Z

 

[weirpig]

1 minute ago, sheikhy said:

Funny thing is this gfs still has uppers of -6 to -8 from 72 hours all the way to 192 hours!!!!its better than the ecm!!!

There really is nothing wrong with it kid   many looking for the next ice age 

[blizzard81]

Absolute top drawer 

[sheikhy]

2 minutes ago, Griff said:

Very consistent GFSP considering with previous... 162

Fantastic run mate!!gfs has snow showers from 96 hours into eastern areas!!!!hows the uppers looking between 96 hours and 192 hours on the para giff?

[Stu_London]

Much better mid term outlook for sustained cold on the 18z.

Sadly FI is pretty close at the moment, so confidence on verification is low.

[Catacol]

A few on here were surprised a day or 3 ago that NWP was amplifying the pattern so much around Jan 2/3/4. We wondered if humans could out think the computer. On this occasion the answer would appear to be yes. GFS run just now has that distinct collapsing rotation to the Griceland ridge....

 

and the same is happening in tonight’s ECM. Run from 96 to 120 to this

 

= clear pattern relax.

2 points from this. As “relaxation” goes this is pretty modest. The block doesn’t even get to the south of England and the easterly flow is maintained. Previous toppler scenarios in past years show the chalk and cheese nature of this season compared to others. The second point is more important. Having recovered confidence in our ability to second guess NWP output it is worth going back to the forecasts that came out a few days ago. Relaxation 2/3/4 Jan and then next waxing of the pattern in and around 6/7/8 Jan as the NY major pacific jet streak adds further wave break tendency to the Atlantic.

ECM tonight for Jan 7 is not too far from the mark probably though I would expect a more vertical surge than this when it comes to it.

It then loses the plot after that - for me at least. Any coincidence this plot loss occurs within 24 hours of the predicted SSW reversal? Maybe...maybe not.... 

Anyway - sticking to the concept of increasingly cold phasing of the wave pattern look to better charts for Jan 6 onwards to begin to firm up. And if we are lucky, just as this amplifying phase turns tepid around Jan 11/12/13 (very approx) we may get SSW impacts flowing through and helping lock in the pattern.

Even a vortex split looks more possible once again on today’s output. Today is a good day for winter optimists.

Edited December 30, 2020 by Catacol

[Stu_London]

Just now, blizzard81 said:

Absolute top drawer 

Topple to Scandi and pull the next trough down from the Arctic - proper Cobra charts would follow with sub -15C 850s

Not going to happen

[Griff]

174 GFS vs p

[Gadje]

14 minutes ago, Geordiesnow said:

Actually I seemed to recalled the effects of that SSW lead to consistent charts barring minor detail changes. The Beast from the east was certain to happen as the models was consistent with it. 

Anyways back to the models, then the UKMO is an improvement regarding the easterly, - 8 uppers hitting the east coast and even a hint of the - 10 uppers in the North Sea. Dissapointing ECM though but it shows why upper air temperatures are more important in a set up where there is wind around especially from the North Sea. 

Regardless, windchill over England especially is going to be felt so it will definately feel raw out there. 

Nope several runs showed it heading too far south, hitting southern France. That was after it looking a cert to arrow in on the UK. Cue the doom, same as now.

[Matt H]

At least there’s no messing around on the pub run, I’ll take this over the shoddy 12z run any day.

Edited December 30, 2020 by Frosty Winter

[kold weather]

18z GFS is about as good as it can get in terms of the synoptic set-up past 144hrs. Its a shame the lower level airflow is too warm when we have that easterly, otherwise it almost certainly could have been a very impressive snowy spell.

Still, the set-up from the 18z GFS is more what we want to see.

As  others have said, when you've got such an extreme pattern developing the models are probably going to be swinging from one extreme to the other quick rapidly given just amplified things are about to get.

[Scott Ingham]

4 minutes ago, Geordiesnow said:

I've no doubt about that as not every SSW leads to a cold spell for the UK but in fairness once the BFTE was nailed, the models were very consistent which made a nice change

GFS 18Z is okay for the easterly but the lack of significant cold uppers means when something more prolonged comes along, it's easier to create that infamous milder sector so instead of snow, it's wet. Higher ground should do pretty good though regardless of uppers so all is not lost. 

 

Yeah i know i agree with you. I was talking about the lead up to the models working out what the end game would be. That period was very chaotic for a week!

[Griff]

2 minutes ago, sheikhy said:

Fantastic run mate!!gfs has snow showers from 96 hours into eastern areas!!!!hows the uppers looking between 96 hours and 192 hours on the para giff?

Some - 8s on the way to this... 

[Catacol]

Haha - just finished my longish post to find that gfs has duly obliged...

[ICE COLD]

I think its cold enough for snow now on the 18z . Love this run

Edited December 30, 2020 by ICE COLD

[blizzard81]

Parallel gets the easterly snow going next Wednesday  

[sheikhy]

Just now, ICE COLD said:

I think its cold enough for snow now on the 18z . Love this run

You got the snow charts for between 96 and 168 hours mate?